Method of controlling electric circuits.



No. 799,053. I P ATENTED SEPT. 12, 1905. P. O. HEWITT. METHOD OF CONTROLLING ELECTRIC CIRCUITS.

APPLICATION FILED AUG.10.1903.

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Wz'ln asses:

UNITED STATES PATENT OFFICE.

PETER COOPER HEWITT, OF NEW YORK, N. Y., ASSIGNOR TO COOPER HEWITT ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

METHOD OF CONTROLLING ELECTRIC CIRCUITS- Specification of Letters Patent.

Patented Sept. 12, 1905.

Application filed August 10, 1903. Serial No: 168,984.

To all whom it may concern.-

Be it .known that I, PETER CooPER HEWITT, a citizen of the United States, and a resident of New York, county of New York, State of New York, have invented certain new and useful Improvements in Methods of Controlling Electric Circuits, of which the following is a specification.

Various applications have been made and proposed in the useful arts of the properties of the gas or vapor electric apparatus invented by me and patented to me under certain of these forms on the 17th day of September, 1901. These applications have for the most part been based upon the action of such apparatus when provided with suitable cooling or heat-dissipating devices whereby the radiation of heat from the apparatus has been made equal to the absorption of the heat in the natural operation of the vapor apparatus.

The present invention contemplates the use of a form of vapor apparatus in which a volatilizable fluid is inclosed within a suitable container and is vaporized by the action of the current.

The invention depends for its utility upon the characteristic possessed by apparatus of this kind of not continuing to carry current when the density of the vapor becomes excessivethat is to say, when the dissipation of heat is not rapid enough to carry off the heat absorbed under the influence of current of definite value. This capacity of the apparatus for heat dissipation may reside in the special construction of the container inclosing the gas or vapor or it may be partly due to the employment of external devices calculated to assist or oppose the normal rate of dissipation.

In the present instance I propose using apparatus of the character described as a circuitbreaker or safety-switch for preventing the flow of an abnormal or dangerous current in the electric circuit.

The drawings Figures 1 and 2 illustrate uses of apparatus of this class, the former showing a direct-current circuit and the latter an alternating-current circuit supplied with safety-switches of the class described.

In Fig. 1 vapor apparatus 1 is introduced into a conductor 2 3 and is adapted to permit a flow of current through it in the direction of the arrow provided the current remains at a definite predetermined normal value.

The apparatus is provided with a small cooling-chamber 4: for assisting in the condensation of the vapors developed in the operation of the devices, and I may surround this coolingchamber with an adjustable dampingshield 5, of metal, adapted to regulate the amount of heat dissipation at the coolingchamber. By the action of the shield the device can be adapted to carry normal currents of diflierent values without the development of excessive density in the inclosed gas or vapor.

We may assume that the apparatus shown in Fig. 1 is capable of transmitting the normal current on the line 2 3. Should a current of abnormal or dangerous value be thrown upon the line, however, the excess of vapor thereby developed inside the containorl would suddenly cause too great a vapor density and the current would cease to flow. In other words, the device acts as a safety-switch and may take the place of an ordinary safety-fuse in the electrical arts. Instead of actually break ing the circuit and interrupting the flow the apparatus may be used to interpose an increased resistance for various purposes.

I have not thought it necessary to illustrate any mode of starting the apparatus in the first instance, but have shown the usual starting-band at 6 and a wire 7, connecting the starting-band with the opposite side of the circuit. The starting may be accomplished through an auxiliary positive electrode, as is well understood, or by automatically or mechanically breaking contact between two electrode-surfaces inside the container.

In Fig. 2 the vapor apparatus 1 is provided with two starting-bands 8 and 9, one near each electrode. The apparatus is here included in one of the mains 10 of an alternating-currentdistribution system, the other main being shown at 11. The vapor apparatus is here shown in shunt to aswitch 12. The function of the vapor apparatus in this case is to prevent excessive sparking or an injurious rise of voltage in the circuit when the switch 12 is opened.

It will be seen that I place between the mains 10 and 11 the primary 13 of a transformer having a secondary 14:, the opposite terminals of which I join by suitable wires 15 and 16 to the starting-bands 8 and 9, respectively. By this arrangement of devices the vapor apparatus 1, which is short-circuited when the switch 12 is closed, will the flow of current when the'normal current when the said switch is opened have impressed upon it not only the full voltage of the current at its electrodes, but also a secondary voltage at the starting-bands. These combined effects are suflicient to start the vapor apparatus and permit a temporary flow of current through it, thus relieving the sparking at the terminals of the switch 12. Any tendency to maintain an alternating flow of current through the vapor device will, however, be defeated by the development of too great density of vapor in the apparatus, which is designed in this instance for suppressing the flow after the first passage of current has performed its function of reliev' ing the hand-switch.

Intermediate points upon the primary 13 and the secondary 14 are shown as being crossconnected. The object is to apply the starting voltage as between each of the several starting-bands 8 and 9 and its neighboring electrode. \Vithout such cross connection between the primary and the secondary the secondary voltage would be applied to the starting-bands alone and the object of applying such secondary voltage would not be attained.

It is evident that the self-restoring feature might be applied to the device illustrated in Fig. 1, in which case the switch would restore itself to the normal working condition after the cessation of the abnormal or dangerous current.

In another application filed by me March 20, 1903, Serial No. 1 5,690, claims are made upon the apparatus described herein.

claim as my invention 1. The method of protecting translating devices in an electric circuit containing a vapor device adapted to carry current of normal value, which consists in causing an abnormal or dangerous current to increase the vapor density to a degree which prohibits the passage of such current.

2.. The method of protecting translating devices in an electric circuit, which consists in transmitting the normal current in such circuit through a gas or vapor conductor, adapting the density of the gas or vapor to the normal current in the circuit, and opposing to an abnormal or dangerous current a vapor density which prohibits the passage thereof.

8. The method of protecting translating devices in an electric circuit, which consists in transmitting the normal current in such circuit through a gas or vapor conductor, adapting the density of the gas or vapor to the normal current in the'circuit, opposing to an abnormal or dangerous current a vapor density which prohibits the passage thereof, and restoring the normal density and permitting l l l is resumed.

4:. In a circuit containing a gas or vapor electric device, and a work-circuit connected in series, the method of protecting translating devices in the work-circuit, which consists in so proportioning the dissipating power and the specific heat of the gas or vapor device that with normal currents no harmful voltage is absorbed by the vapor while under abnormal current the pressure of the vapor is so increased as to interrupt the flow of the current.

5. The method of preven tin g the occurrence of an excessive discharge-spark at a switch upon the interruption of the connections of a work-circuit, including a gas or vapor device in shunt upon the switch, which consists in opening the switch connections and generating in the vapor device by the resultant current flowing therethrough to the work-circuit, a vapor-pressure offering a prohibitive resistance to the continued passage of the current.

6. The method of interrupting the flow of an alternating current through a work-circuit without injurious sparking at the contacts of the circuit-breaker, which consists in momentarily passing, upon the separation of the contacts, a current to the work-circuit through a gas or vapor path, and developing within said path a resistance suliicicnt to prevent the continued passage of current to the work-circuit.

7. The method of controlling the flow of current in an electric circuit, which consists in transmitting the normal current in such circuit through a gas or vapor conductor, adapting the pressure of the gas or vapor to the normal current in the circuit, and varying the said prcssu re within any desired limits under the influence of an abnormal current.

8. The method of interrupting the flow of an alternating current through a work-circuit without injurious sparking at the contacts of the usual circnit-breaker, which consists in momentarily passing, upon the separation of the circuit-breaker contacts, a current to the work-circuit through a gas or vapor path, simultaneously impressing upon the said gas or vapor path a secondary voltage, and developing within said path a resistance suflicicnt to prevent the continued passage of current to the work-circuit.

Signed at New York, in the county of New York and State of New York, this (5th day of August, A. D. 1903.

PETER COOPER HEW 1T l/Vitnesses:

WM. H. Caren, Gnonen H. STOOKBRIDGE. 

